The invention relates to a writing utensil, comprising a container having an opening, in which container writing liquid is freely received, one conveying line that is at least partially capillary for the writing liquid, that connects the container to the writing tip for conveying the writing liquid, and a capillary storage communicating with the conveying line.
In writing utensils of this kind a classical closed system is present in which the writing liquid is prevented from leakage by vacuum. For example, fountain pens that have been known for decades are designed according to such a system. Writing utensils of this kind have a special disadvantage that is experienced by almost all users of fountain pens in a more or less misfortunate manner. When the container containing the writing liquid in a free manner, i.e., in a non-capillary manner, has been emptied partially by using the writing utensil, in the writing position of the writing utensil writing liquid may escape from the container due to temperature related air expansion. In order to be able to receive this writing liquid in such a scenario at least partially, i.e., that portion that in general would escape due to air expansion, a capillary storage is provided, for example, in a fountain pen under the pen nib. The capillarity of such a storage must be so great that in the writing position the writing liquid cannot leak from it, but, on the other hand, so small that the storage is not filled during normal writing operation, thus being unable to receive the writing liquid during the aforementioned scenario of air expansion. Such a capillary relation is, as is known in the prior art, to a certain degree realized in classical fountain pens.
However, it has been demonstrated that this solution, due to the relatively narrow limits of air expansion and the relatively small volume of writing liquid in the container for which this known system is operable, cannot be employed for larger containers for writing liquids and for greater limits of air expansion.
It is an object of the present invention to provide a writing utensil of the aforementioned kind that, for great air expansion fluctuations and also for a great container volume in comparison to known systems, functions reliably for receiving writing liquid without allowing the uncontrolled leakage of writing liquid from the writing utensil, independent of the momentary filling degree of the container with writing liquid, whereby the writing utensil should be simple and inexpensive in its production.